Process and apparatus for cracking petroleum



Juy l0, 1928, 1,676,895

L. J. GARY PROCESS AND APPARATUS FOR CRACKING PETROLEUM Original Filed March 14. 1921 2 Sheets-Sheet 2 www.

Patented July 1o, 192s.

UNITED gSfllA-Tls-S'` '1.676.895 PATENT oFF-ICE.

EEE J. GABY, oE CHICAGO, rumors, AssIeNoamo UNIVERSAL orr. rnonne'rs cola:- e rm, or. cnxcaeo, minors, a coEroaATIoN or' sourir DAKOTA.

rEocEss Am) arrnna'rus Eon cnacxme PETROLEUM.

l: Application filed l'arch 14, Serial This invention relates to improvements fa process and ap aratus for cracking petroleum .oils and re moreparticularly .to aV process in whiehvthe oil isheated Vin a cono tinuous'coil and then delivered to expansion chambers Where vapori'zation takes place,

' the carbonis precipitated and the vapors drawn oi and condensed and collected.

- The present inventipn refers more particularly. to the manner of maintaining'a bal-v fanced ressure'inf a=battery lof stills or battery .o expansion chambers. InA the present invention, balancing pressure may be obtained either 'from a gas header Vleading- V1li 'from the expansion chambers orV from a gas header leadingA from the dephlesgmators orreliux condensers This 1willpermit of' maintainin the. water condensers andreceivers u'n er a reduced pressure from the restofthe system or evenjat atmospheric pressure or under'a vacuum. -The present invention also permits of a balance pressure being .maintained on. the expansion chambersA and a separate .balanced pressure' maintained on the reflux condensers if desirable.' lathe' craclng of petroleum 011, 1t 1s very desirable tomain'tain close adJustments of pressure on various parts ofthe stem,

which is accomplished by the present mvenv-A' tion in a .simple manner.

' Inthe drawings: n

Fig. 1 is a to'p planview of'my improved apparatus. l Fig. 2 is a view, artly in sideelevation 85 and partly in vertic'a section, ofthe same.

Referring in detail to the drawings,j1, 2

and3 designate thejfurnaces in which are'.

.mountedthe heating coils 4 which may ta ke the4 form of continuous lengths of 4" pipe.

Each 'coil 4 is' connectedtoa' feedpump 5' 'nected by transerline` 6 in which 4is inter'- posed a throttle valve 7 to a transfer'header 8. Each transfer header.' 8. is connected by may be simultaneously used. vEach' e an.

sion chamber '10 is provided 'witha resldue drawoi pipe 11,'controlled by'throttle valve Y 5.5 12 and with'vapor outlet lpipe 13 controlled trolled by throttle valve 17, lea 1n back to `vpipe 35 controlledby vthrottle valve 36 and drawn o fromv timeto "time either for test be automatically-maintained on all of the leading .to anysuitable source of .raw o1l sup.v

ply. The discharge sideof each coil is :con-.' In such case', the dephlegmators andthe rest 'coils and receivers. 'Q1' as another way of rrp. 452,314. Renewed :reliquia-yv ao, 1938.7.

by throttle valve 14, which pipe 13 extends into the lower side of a vertlcal dephlegmator 15. From the lower part of each dephlegmator 15 extends a -reux pi e 16 conco the corres onding feed pum 5. etop of each fdep egmator is provi ed witha vapor outlet pipe 18 controlled by throttle valve 19 andleading to the top of condenser coil 20' -seated in condenserbox 21. The lower end 'e5 10i eachcoil 20 is connected by pipe 22. having throttle 4valve 23 tothe top of receiver Eachlreceiver 24 is provided with pressure gauge 25, liquid level gauge26, liquid drawoi pipe 27 controlled by throttlevalve lo 28'andi gas outlet pipe 29 controlled by throttle valve 30. Each receiver is also provided with a pipe 31 .having throttle valve 32 and leading to a vacuum pump 33.- Where the vacuum umps are used, the receivers may 1I- be provi ed with vacuum gauges'34.

Referring now more -partiularly to the novel features of the invention; from each expansion chamber 10 extends'a shortriser leading to a gas header.37,which gas header 37 1s controlled by a master control throttle .valve 38., .The condensable, vapors which pass -np` into this header .wll-be condensed and fall back into `the'expansion chamber so that in eifect the headers willfprimarily cone header may be provided with a liquid-trap (n ot shown) whereby condensate may be.

purposes or -to remove the condensate from the jheade'r. Inasmuch as all `of'the'eirpan'-` sionl chambers are connected to this header, it willibe seen that a uniform pressure may expansion chambers and heating elements.

operating the process, a ressure 'of 300 pounds may be maintain onthe heatingtubes'pnd expansion chambers and a vacuum resem 15" a entf-1....muainea on am. dephlegmator, condenser coil andreeeivers. no

` trolled b I I'h-ave above described the use of a header connected to the expansion chambers. In additiomI provide a second header -39-c0n-` connecte by .thelbranch pipes 41 having throttle valves 42 to the dephlegmators. This header may operate in exactly the same way as the header previously' described to maintain a balanced pressure on'the dephleg mators, expansion chambers and heating coils. In such case, the valves 7 and 14' will be openedl and the pressure regulated by the various valves 19V. In this case, a 200 to 300 pounds pressure maybe maintained' from the heating coils through'the dephlegmators anda reduced pressure, 'or even atmospheric, or even a vacuum, maintained Qn the various condenser coils and receivers. In such case, the header 37 may be cut out of the system by closing the various valves 36 in the branch pipes 35.

It has been obvious to those versed inV the art of cracking hydrocarbon oils that the use of differential pressures as explained willresult. in an increased yield of light hydrocarbons from certain ty es of charging stock. Infact, due to the rictional resistance encountered in the flow of oil from the l heating coils to the receiver, there is always a slight reduction in pressure, that is, there is a slightly higher pressure maintained on `duction in pressure, an determined relatively high pressureon the theheating coils than on thecondenserand receiver, in `order to force the oil and vapors through the system. B regulating this remantaining a predephlegmator and throttllng the pressure on the flow to the condenser, it is possible to -accurately reduce it and operate under a relatively low pressure. Numerous experiments .have proven the advantage of this reductlon in pressure and condensing under a lower pressure than the pressure on the.

dephlegmator in certain types of oils."-

As still anothermethod 'of operating the.

process, both of the headers may be used',

in which case a pressure of 250 pounds Amay be maintained on the expansion chambers and heating coils and the balancing effect produced on these elements from the header 37. A' reduced pressure of say, 150 pounds a master throttle valve 40 and' may be maintained on the various dephlegmators by suitably throttling the valves 14` and 1,9v and opening the various valves 42.' In this case, the reduced ressure .or vacuum may be maintained on t e condenser coils Aand receivers'.l

It is to beunderstoodthat I have here which control the headers.; It `is to'be lunderstood that the` other valves shown maybe .referred l more vparticularly t'o the valves suitably operated to regulate the pressure and also, for example, to cut any part of the apparatus out of the system.

I claim as my invention: 1. An apparatus for cracking hydrocarbon oil, comprising aplurality of independent heating coils, a plurality of expansion chambers, intowhich heated oil from vsaid coils is discharged, a dephlegmator associated with each of said enlarged expansion chambers, pressure. reducing means interposed `between eachenlargedv expansion chamber and its associate dephlegmator, a common header in. communication with the vapor space of each of said expansion chambers, a second header in communication with each of said dephlegmators, whereby a uniform pressure can be maintained in said dephlegmators, lowerthan a uniform superatmospheric pressure maintained in said enlarged expansion chambers, and means connected to sa'id dephlegmators for condensing and collecting vapors issuing therefrom.

"-2. A continuous process for cracking oil,

consisting in simultaneously assing a luatmospheric pressure higher than the uniform pressure maintained in said dephlegf mators, and in takin off uncondensed vapors from said dep egmators for condensation and collection.

l LEE J. GARY. 

